Pyrotechnic linear actuators may be used to move surfaces on or portions of a vehicle to protect a pedestrian in the event of impact with the vehicle. For example, linear actuators may be disposed below a portion of the hood to lift the hood of the vehicle to a defined stroke (distance) within a certain time frame in the event of a pedestrian impact. The vehicle manufacturer may set specifications as to the defined stroke and time frame, as well as a de-pressurization time frame and/or maximum force target for returning the vehicle part moved by the linear actuator to its pre-deployed position (e.g., within 2 seconds or using less than 200 Newtons). The de-pressurization time frame and/or force targets can be challenging or impossible to achieve with a post deployed actuator that is retaining gas pressure.
Thus, there is a need in the art for an improved actuator that is tunable to the vehicle manufacturer's specifications.